Method for improving curvature of the polished surface by chemical mechanical polishing

ABSTRACT

This invention relates to a method for improving curvature of the polished surface by chemical mechanical polishing comprising a polishing table, a polishing pad, a polishing head and a slurry exhaust system. The polishing head comprises a revolving spindle and the slurry exhaust system comprises a slurry outlet. The method for improving curve rate of the polished surface by chemical mechanical polishing is in order to make the slurry distributing on the polishing pad non-uniformly in controlling to control removing rate on each point of the polishing surface by the concentration of the slurry. This method will improve the defects in non-smooth on the wafer-polishing surface to make the wafer-polishing surface in full flatness after polishing.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] This invention relates to a method for changing curvature of the polished surface in the chemical mechanical polishing (CMP) process, and more particularly to a way for providing slurry in the chemical mechanical polishing process. We can control the velocity in removing rate by controlling the concentration of slurry distributing on the polishing pad to obtain a better smooth surface after polishing.

[0003] 2. Description of the Prior Art

[0004] Chemical mechanical polishing is a method of polishing materials, such as semiconductor substrates, to a high degree of planarity and uniformity. The process is used to planarize semiconductor slices prior to the fabrication of microelectronic circuitry thereon, and is also used to remove high elevation feature created during the fabrication of the microelectronic circuitry on the substrate. One typical chemical mechanical polishing process uses a large polishing pad, located on a rotating platen, against which a substrate is positioned for polishing, and a carrier which biases and positions the substrate on the rotating polishing pad. A chemical slurry, which may also include abrasive materials therein, is maintained on the polishing pad to enhance the polishing of the substrate.

[0005] The use of chemical mechanical polishing to planarize semiconductor substrates has met with universal acceptance, particularly where the process is used to remove high elevation features created during the fabrication of microelectronic circuitry on the substrate. One primary problem which has limited the use of chemical mechanical polishing in the semiconductor industry is the limited ability to predict, much less control, the rate and uniformity at which the process will remove material from the substrate. As a result, chemical mechanical polishing is a labor intensive process, because the thickness and uniformity of the substrate must be constantly monitored to prevent over-polishing or inconsistent polishing of the substrate surface.

[0006] One factor which contributes to the unpredictability and non-uniformity of the polishing rate of the chemical mechanical polishing process is the non-homogeneous replenishment of slurry at the interface of the substrate and the polishing pad. The slurry is primarily used to enhance the material removal rate of selected materials from the wafer surface. As a fixed volume of slurry in contact with the substrate reacts with the selected materials on the substrate surface, the fixed volume of slurry becomes less reactive and the polishing enhancing characteristics of that fixed volume of slurry are significantly reduced. One approach to overcoming this problem is to continuously provide fresh slurry onto the polishing pad. This approach presents at least two difficulties. Because of the physical configuration of the polishing apparatus, introducing fresh slurry into the area of contact between the substrate and polishing pad is difficult, and providing a consistently fresh supply of slurry to all portions of the substrate is even more difficult. As a result, the uniformity and overall rate of polishing are significantly affected as the slurry reacts with the substrate.

[0007] Several methods have been proposed for maintaining fresh slurry at the substrate-polishing pad interface. One method allows the substrate to “float” on the polishing pad. The object of floating the substrate on the polishing pad is to provide a very small downwardly directed force at the substrate-polishing pad interface, so that slurry will flow between the substrate and the polishing pad. This method is ineffective because the slurry is still substantially prevented from moving under the substrate by surface tension and other factors, and the use of a low force at the substrate-polishing pad interface substantially increases the cycle time necessary to polish a substrate.

[0008] Another method of providing slurry to the face of the substrate engaged against the polishing pad uses a plurality of holes in the platen, and the slurry is injected through the holes and underside of the polishing pad. The object of this method is to ensure that the slurry is constantly replenished at the substrate-polishing pad interface through the underside of the polishing pad.

[0009] Particles in slurry and polishing pad are used for polishing to wafers in chemical mechanical polishing. It is an important object to make wafers surface to achieve a standard of request in full flatness after polishing. In the traditional chemical mechanical polishing process, we think up a method to make slurry distributing on the polishing pad uniformly to get the same removal velocity on each point of the wafer surface. A prerequisite condition of this method is the wafer surface to be in full flatness before polishing. The wafer surface just keeps in full flatness after uniformly polishing.

[0010] But wafers in thermal oxide and chemical deposition preprocess are usually influenced by outside parameters. The wafer surface is not in full flatness before polishing in chemical mechanical polishing process. If the wafer pass through the uniformly chemical mechanical polishing process, the wafer surface is still not in full flatness. This kind of condition increases the rate of bad products and enhances the producing cost. Therefore, how to make chemical mechanical polishing process in non-uniformly polishing to be controlled is the developing key point in the chemical mechanical polishing process at present.

SUMMARY OF THE INVENTION

[0011] In accordance with the above-mentioned invention backgrounds, the traditional chemical mechanical polishing process makes slurry distributing on the polishing pad uniformly and makes the same removing rate on each point of the wafer surface. These conditions will make the back-end process not to solve the defects from pre-process. The present invention provides a method for controlling the concentration of slurry on the polishing surface to go a step further to control removing rate on each point of the polishing surface. Therefore, the back-end processes have ways to solve the defects from pre-process.

[0012] The second object of this invention is to make the polishing surface in full flatness by slurry distributing on the polishing pad non-uniformly to be controlled.

[0013] The third object of this invention is to make the polishing surface having better surface qualities by different slurry exhaust positions. This condition makes slurry distributing on the polishing pad non-uniformly to be controlled.

[0014] The fourth object of this invention is to reduce production costs by improving the rate of bad wafer products after chemical mechanical polishing process.

[0015] The fifth object of this invention is to make slurry distributing on the polishing pad non-uniformly to be controlled by different slurry exhaust positions. Then, the concentration of slurry distributing on the polishing pad is non-uniformly and removing rate on each point of polishing surface is controlled. This condition will make the whole process more smooth and increase the efficiency of the process.

[0016] It is a further object of this invention is to reduce time in adjusting and testing machines, to increase the velocity of manufacture and to reduce time in servicing machines.

[0017] In according to the foregoing objects, The present invention provides a method for making slurry distributing on the polishing pad non-uniformly by controlling different concentrations of slurry distributing on the polishing pad to get different removing rate on each point of polishing surface. Besides solving defects in surface not in full flatness from pre-process and increasing the quality and smooth of the polishing surface after chemical mechanical polishing, this method can also reduce the rate of bad products.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same becomes better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:

[0019]FIG. 1 shows a vertical view diagram of the chemical mechanical polishing process in using movable slurry feeding mechanism;

[0020]FIG. 2 shows a diagram of the movable slurry feeding mechanism in pre-mixing slurry and chemical solution in chemical mechanical polishing process;

[0021]FIG. 3 shows a diagram of the movable slurry feeding mechanism in separate supplying slurry and chemical solution at the same position on polishing pad in chemical mechanical polishing process;

[0022]FIG. 4 shows a diagram of the movable slurry feeding mechanism in separate supplying slurry and chemical solution at the same position on polishing pad in chemical mechanical polishing process;

[0023]FIG. 5 shows a diagram of the slurry and chemical solution to be added on the polishing pad from lower of the polishing table in chemical mechanical polishing process;

[0024]FIG. 6 shows a diagram of the slurry distributing on the polishing pad;

[0025]FIG. 7 shows a diagram of the movable slurry feeding mechanism in premixing slurry and chemical solution on the linear polishing table in chemical mechanical polishing process;

[0026]FIG. 8 shows a diagram of the movable slurry feeding mechanism in separate supplying slurry and chemical solution at the same location on the linear polishing pad in chemical mechanical polishing process;

[0027]FIG. 9 shows a diagram of the movable slurry feeding mechanism in separate supplying slurry and chemical solution at different locations on the linear polishing pad in chemical mechanical polishing process; and

[0028]FIG. 10 shows a compared diagram of the wafer surface condition in using chemical solution or not after chemical mechanical polishing process.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0029] The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same becomes better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:

[0030] It is very important in slurry distributing condition on the polishing pad of chemical mechanical polishing process. Because slurry distributing condition on the polishing pad affects removing rate to make incomplete flat surface after polishing, on the traditional chemical mechanical polishing mechanism, the slurry feeding system is a fixed means locating on the better slurry exhaust place after considering. The request with an emphasis is to make slurry distributing on the polishing pad uniform. In other words, the request is to make concentration of slurry distributing on the polishing pad uniformly. This condition makes removing rate on each point to be the same of polishing surface to get a final object in getting full flatness surface.

[0031] When more slurry be added to partial polishing surface, the added polishing particles of slurry are enough and removing rate is faster. This condition lets the partial polishing surface to be lower than other sections after polishing. More slurry on polishing process causes better lubricity and gets better qualities of polishing surface after polishing. When less slurry be added to partial polishing surface, the added polishing particles of slurry are not enough and removing rate is slower. This condition makes the partial polishing surface to be higher than other sections after polishing. Less slurry on polishing process causes less lubricity and has defects from bigger drag friction. Therefore, traditional chemical mechanical polishing requires slurry distributing on the polishing pad uniform to get better qualities of polishing surface after polishing.

[0032] We almost suppose the wafer polishing surface to be in full flatness before polishing in general traditional chemical mechanical polishing. The object of polishing is to reduce the thickness of the wafer and gets the thickness of the wafer for requests. However wafers in thermal oxide and chemical deposition pre-process are usually influenced by outside parameters. The wafer surface is not in full flatness before polishing in chemical mechanical polishing process. If the wafer pass through the uniformly chemical mechanical polishing process, the wafer surface is still not in full flatness. The present invention provides a method for making slurry distributing on the polishing pad non-uniformly by controlling different concentrations of slurry distributing on the polishing pad to get different removing rate on each point of polishing surface. This condition makes wafer polishing surface to reach smooth surface which we need.

[0033] When the thickness of portion of the wafer which is produced from pre-process is higher, we must offer higher concentration of slurry on chemical mechanical polishing process. In other words, we must offer more amount of polishing particles participating in polishing reactions to get higher removing rate. When the thickness of portion of the wafer which is produced from pre-process is lower, we must offer lower concentration of slurry on chemical mechanical polishing process. In other words, we must offer less amount of polishing particles participating in polishing reactions to get less removing rate. We can get better qualities of the polishing surface by controlling the concentration of slurry or the amount of slurry distributing on the polishing pad after polishing to solve problems to be brought from pre-process.

[0034]FIG. 1 shows a vertical view diagram of the chemical mechanical polishing process. At first, the chip is placed on the polishing table and is pressurized by a head to increase removing rate. And then the chip is polished by polishing pad and slurry. Using the present invention method, we observe surface condition of the wafer before polishing at first. Then, we decide positions of the slurry exhaust mechanism A, B, and C. When slurry exhaust positions are different, the slurry distributing conditions are also different on the polishing surface to affect removing rate on each point of the polishing surface. We must observe surface condition of the polishing wafer to adjust slurry exhaust positions and use slurry distribution on the polishing pad to make different removing rates. Finally, we can get better surface qualities of the wafer after polishing.

[0035]FIG. 2 shows a diagram of the chemical mechanical polishing process in using the present invention method. The chip 21 is placed on the polishing table 10 and is pressurized by a head 20 to increase removing rate. One revolving spindle 15, which is parallel to the axis of the head, under the polishing table 10 rotates the polishing table 10. The other revolving spindle 22 above the head 20 rotates the head 20. We use the polishing pad 11 and slurry which is added from a slurry exhaust system 30 polishing to the wafer 21. The slurry exhaust position is placed above the polishing table in the same direction of the head 20.

[0036] In the present invention, the slurry exhaust system 30 is a movable slurry exhaust mechanism which is comprising a rotated or movable baton element. The center axis of the rotated baton element is parallel to the axis of the head. We observe wafer 21 surface conditions to adjust positions of the slurry exhaust system. The slurry exhaust system of this invention comprises two inlets. The common slurry 31 is flowing in one inlet 42 and the chemical solution 33 is flowing in the other inlet 40. The pH value in using chemical solution 33 is similar to the slurry 31. The function of chemical solution 33 is to dilute the slurry and not to cause a bad chemical reaction with wafer surface. In the chemical mechanical polishing process, we can observe the surface conditions before polishing and adjust the concentration of slurry before sending the slurry to make different concentrations of slurry on each contacting point of the polishing surface. This condition creates the different removing rates on each point of polishing surface. The points, which need a large amount of polishing, also need a higher concentration of slurry to increase removing rate. The points, which need a small amount of polishing, also need a lower concentration of slurry to reduce removing rate. This condition lets polishing surface reach the required standard after the CMP process.

[0037]FIG. 3 shows a diagram of the chemical mechanical polishing process in using the present invention method. At first, the chip 21 is placed on the polishing table 10 and is pressurized by a head 20 to increase removing rate. One revolving spindle 15, which is parallel to the axis of the head, under the polishing table 10 rotates the polishing table 10. The other revolving spindle 22 above the head 20 rotates the head 20. We use the polishing pad 11, slurry 31, and chemical solution 33 to polish the wafer 21. The slurry exhaust position is above the polishing table in the same direction of the head 20.

[0038] There are two slurry exhaust systems in the present invention. The common slurry 31 is flowing in one system 37 and the chemical solution 33 is flowing in the other system 35. The two slurry exhaust systems are comprising a rotated or movable baton element in each other. The central axis of the rotated baton element is parallel to the axis of the head. The pH value in using chemical solution 33 is similar to the slurry 31. The function of the chemical solution 33 is to dilute the slurry 31 and not to cause a bad chemical reaction with wafer surface. There is a length of distance between the two slurry exhaust systems. In the chemical mechanical polishing process, we can observe the surface conditions before polishing and decide the points, which need higher removing rate or lower removing rate. We only add slurry on the points, which need to be given in higher removing rate. On the points which need to be given lower removing rate, we must add chemical solution to slurry to dilute concentration of slurry on the polishing pad and to reduce the particle density of slurry to get lower removing rate. This condition lets polishing surface to reach a needed standard after CMP process.

[0039]FIG. 4 shows a diagram of the chemical mechanical polishing process in using the present invention method. At first, the chip 21 is placed on the polishing table 10 and is pressurized by a head 20 to increase removing rate. One revolving spindle 15, which is parallel to the axis of the head, under the polishing table 10 rotates the polishing table 10. The other revolving spindle 22 above the head 20 rotates the head 20. We use the polishing pad 11, slurry 31, and chemical solution 33 to polish the wafer 21. The slurry exhaust position is above the polishing table in the same direction of the head 20.

[0040] There are two slurry exhaust systems in the present invention. The common slurry 31 is flowing in one system 37 and the chemical solution 33 is flowing in the other system 35. The two slurry exhaust systems are comprising a rotated or movable baton element in each other. The central axis of the rotated baton element is parallel to the axis of the head. The pH value in using chemical solution 33 is similar to the slurry 31. The function of the chemical solution 33 is to dilute the slurry 31 and not to cause a bad chemical reaction with wafer surface. The length between the two slurry exhaust systems is very short. In the chemical mechanical polishing process, we can observe the surface conditions before polishing and decide the points which need higher removing rate or lower removing rate. In the chemical mechanical polishing process, we control concentration of slurry by mixing the slurry and the chemical solution on the polishing pad to make different concentration of slurry on the points of polishing surface and different removing rate on each point of polishing surface. The points, which need a large amount of polishing, contact higher concentration of slurry to increase removing rate. The points, which need a small amount of polishing, contact lower concentration of slurry to reduce removing rate. This condition lets polishing surface to reach a needed standard after the CMP process.

[0041]FIG. 5 shows a diagram of the chemical mechanical polishing process in using the present invention method. The chip 21 is placed on the polishing table 10 and is pressurized by a head 20 to increase removing rate. One revolving spindle 15, which is parallel to the axis of the head, under the polishing table 10 moves the polishing table 10 in orbital track. The other revolving spindle 22 above the head 20 rotates the head 20. We use the polishing pad 11, slurry 31, and chemical solution 33 to polish the wafer 21. The slurry exhaust position is on the polishing table and slurry is provided from a place below the polishing table to the polishing pad in the chemical mechanical polishing process. Referring to FIG. 6, there are two regions D and E, in different concentrations on the polishing pad 11 to control the profiles of the wafer after polishing.

[0042] In the present invention, the slurry is sent from slurry exhaust system under the polishing table. We observe wafer 21 surface conditions to adjust positions of the slurry exhaust system. The slurry exhaust system of this invention comprises two inlets. The common slurry 31 is flowing in one inlet 42 and the chemical solution 33 is flowing in the other inlet 40. The pH value in using chemical solution 33 is similar to the slurry 31. The function of chemical solution 33 is to dilute the slurry and not to cause a bad chemical reaction with wafer surface. In the chemical mechanical polishing process, we can observe the surface conditions before polishing and adjust the concentration of slurry before sending the slurry to make different concentrations of slurry on each contacting point of the polishing surface. This condition creates the different removing rates on each point of polishing surface. The points, which need a large amount of polishing, also need a higher concentration of slurry to increase removing rate. The points, which need a small amount of polishing, also need a lower concentration of slurry to reduce removing rate. This condition lets polishing surface reach the required standard after the CMP process.

[0043]FIG. 7 shows a diagram of the chemical mechanical polishing process in using the present invention method. It is another embodiment of the present invention. The polishing table 13 over here provides a kind of linear moving table. The surface of the polishing pad is perpendicular to the axis of the head. The moving direction of the polishing surface is perpendicular to the axis of the head. Pieces of oblong polishing pad 11 are stuck on the polishing table. Wafers 21 are fixed and rotated by heads 20 on the polishing pad 11. Using a movable slurry exhaust mechanism 30 provides slurry in polishing. The scope of operation in movable slurry exhaust mechanism 30 is about the width of the polishing table L. The slurry exhaust position is above the polishing table 10 in the same direction of the head 20.

[0044] In the present invention, the slurry exhaust system 30 is a movable slurry exhaust mechanism. We observe wafer 21 surface conditions to adjust positions of the slurry exhaust system. The slurry exhaust system 30 of this invention comprises two inlets. The common slurry 31 is flowing in one inlet and the chemical solution 33 is flowing in the other inlet. The pH value in using chemical solution 33 is similar to the slurry 31. The function of chemical solution 33 is to dilute the slurry and not to cause a bad chemical reaction with wafer surface. In the chemical mechanical polishing process, we can observe the surface conditions before polishing and adjust the concentration of slurry before sending the slurry to make different concentrations of slurry on each contacting point of the polishing surface. This condition creates the different removing rates on each point of polishing surface. The points, which need a large amount of polishing, also need a higher concentration of slurry to increase removing rate. The points, which need a small amount of polishing, also need a lower concentration of slurry to reduce removing rate. This condition lets polishing surface reach the required standard after the CMP process.

[0045]FIG. 8 shows a diagram of the chemical mechanical polishing process in using the present invention method. It is another embodiment of the present invention. The polishing table 13 over here provides a kind of linear moving table. The surface of the polishing pad is perpendicular to the axis of the head. The moving direction of the polishing surface is perpendicular to the axis of the head. Pieces of oblong polishing pad 11 are stuck on the polishing table. Wafers 21 are fixed and rotated by heads 20 on the polishing pad 11. Using a movable slurry exhaust mechanism 30 provides slurry in polishing. The scope of operation in movable slurry exhaust mechanism 30 is about the width of the polishing table L. The slurry exhaust position is above the polishing table 10 in the same direction of the head 20.

[0046] There are two slurry exhaust systems in the present invention. The common slurry 31 is flowing in one system 37 and the chemical solution 33 is flowing in the other system 35. The two slurry exhaust systems are comprising a rotated or movable baton element in each other. The central axis of the rotated baton element is parallel to the axis of the head. The pH value in using chemical solution 33 is similar to the slurry 31. The function of the chemical solution 33 is to dilute the slurry 31 and not to cause a bad chemical reaction with wafer surface. The length between the two slurry exhaust systems is very short. In the chemical mechanical polishing process, we can observe the surface conditions before polishing and decide the points which need higher removing rate or lower removing rate. In the chemical mechanical polishing process, we control concentration of slurry by mixing the slurry and the chemical solution on the polishing pad to make different concentration of slurry on the points of polishing surface and different removing rate on each point of polishing surface. The points, which need a large amount of polishing, contact higher concentration of slurry to increase removing rate. The points, which need a small amount of polishing, contact lower concentration of slurry to reduce removing rate. This condition lets polishing surface to reach a needed standard after the CMP process.

[0047]FIG. 9 shows a diagram of the chemical mechanical polishing process in using the present invention method. It is another embodiment of the present invention. The polishing table 13 over here provides a kind of linear moving table. The surface of the polishing pad is perpendicular to the axis of the head. The moving direction of the polishing surface is perpendicular to the axis of the head. Pieces of oblong polishing pad 11 are stuck on the polishing table. Wafers 21 are fixed and rotated by heads 20 on the polishing pad 11. Using a movable slurry exhaust mechanism 30 provides slurry 39 in polishing. The scope of operation in movable slurry exhaust mechanism 30 is about the width of the polishing table L. The slurry exhaust position is above the polishing table 10 in the same direction of the head 20.

[0048] There are two slurry exhaust systems in the present invention. The common slurry 31 is flowing in one system 37 and the chemical solution 33 is flowing in the other system 35. The two slurry exhaust systems are comprising a rotated or movable baton element in each other. The central axis of the rotated baton element is parallel to the axis of the head. The pH value in using chemical solution 33 is similar to the slurry 31. The function of the chemical solution 33 is to dilute the slurry 31 and not to cause a bad chemical reaction with wafer surface. There is a length of distance between the two slurry exhaust systems. In the chemical mechanical polishing process, we can observe the surface conditions before polishing and decide the points, which need higher removing rate or lower removing rate. We only add slurry on the points, which need to be given in higher removing rate. On the points which need to be given lower removing rate, we must add chemical solution to slurry to dilute concentration of slurry on the polishing pad and to reduce the particle density of slurry to get lower removing rate. This condition lets polishing surface to reach a needed standard after CMP process.

[0049]FIG. 10 shows a compared diagram of the wafer surface condition in using chemical solution or not after chemical mechanical polishing process. The curve line connecting the signals “▴” show the surface condition after polishing without adding the chemical solution to slurry in chemical mechanical polishing process. The curve line connecting the signals “▪” show the surface condition after polishing with adding the chemical solution to slurry in chemical mechanical polishing process. From the diagram, we can know that the curvature of the curve line of the wafer surface to be measured is more smooth with using the slurry which is added the chemical solution in the chemical mechanical polishing process. This means that the smooth of the wafer surface is better after polishing. The condition of the wafer surface to be measured after polishing is a kind of shapes like sawteeth without adding chemical solution to the slurry in the chemical mechanical polishing process. This means that the smooth of the wafer surface is worse after polishing. Thereby we can prove that adding chemical solution to the slurry will make slurry distributing on the polishing pad non-uniformly in controlling to get better smooth of the wafer surface after polishing.

[0050] In the competition violent society at present, production capacities and production qualities are the request emphasis in each factory. If we still use prior arts in chemical mechanical polishing process, we will not have abilities to increase production capacities and production qualities and will have to be weeded. The present invention makes slurry distributing on the polishing pad non-uniformly in controlling to get different removing rates on each point of the polishing surface. We can get better smooth of the wafer surface after polishing and overcome the defects on the polishing surface in pre-process to increase the qualities of the production and to reduce the cost. We also can reduce the time in adjusting parameters of chemical mechanical polishing mechanism to increase the rate of production.

[0051] In accordance with the present invention, a main object of this method is to make slurry distributing on the polishing pad non-uniformly in controlling by using a movable slurry exhaust mechanism and adding chemical solution to slurry to increase surface qualities after polishing and to reduce the time in adjusting parameters of chemical mechanical polishing mechanism. We can also solve defects in not full flatness from pre-process on wafer surface.

[0052] Although specific embodiments have been illustrated and described, it will be obvious to those skilled in the art that various modifications may be made without departing from what is intended to be limited solely by the appended claims. 

What is claimed is:
 1. A method for improving polishing surface qualities in chemical mechanical polishing process, said method comprising: laying a polishing pad on a polishing table; using a movable slurry exhaust mechanism to provide a mixed slurry on said polishing pad, said mixed slurry comprising a chemical solution and a slurry; placing a wafer on the polishing pad by a head; and polishing said wafer by using said mixed slurry and said polishing pad.
 2. The method according to claim 1, wherein said polishing table is a table adapted to polishing said wafer.
 3. The method according to claim 2, wherein said polishing table is a linear movable, the moving direction of a polishing surface on said linear movable polishing table is perpendicular to the axis of said head.
 4. The method according to claim 2, wherein said polishing table is rotatly movable and is rotated by a revolving spindle which is parallel to the axis of said head.
 5. The method according to claim 1, wherein said wafer is further comprising a substrate and a polishing layer.
 6. The method according to claim 1, wherein said movable slurry exhaust mechanism is a rotated baton element and the central axis of said movable slurry exhaust mechanism is parallel to the axis of said head.
 7. The method according to claim 6, wherein said movable slurry exhaust mechanism further comprises a fluid outlet.
 8. The method according to claim 1, wherein said mixed slurry further comprises a fluid with small particles.
 9. The method according to claim 1, wherein said chemical solution is unable to cause a bad chemical reaction with wafer polishing surface.
 10. A method for improving polishing surface qualities in chemical mechanical polishing process, said method comprising: laying a polishing pad on a polishing table; using a movable slurry exhaust mechanism to provide slurry on said polishing pad; using a movable chemical solution exhaust mechanism to provide chemical solution on said polishing pad; placing a wafer on the polishing pad by a head; and polishing said wafer by using said slurry, said chemical solution and said polishing pad.
 11. The method according to claim 10, wherein said polishing table is a table adapted to polishing said wafer.
 12. The method according to claim 11, wherein said polishing table is linear movable, the moving direction of a polishing surface on said linear movable polishing table is perpendicular to the axis of said head.
 13. The method according to claim 11, wherein said polishing table is ratatly movable and is rotated by a revolving spindle which is parallel to the axis of said head.
 14. The method according to claim 10, wherein said wafer further comprises a substrate and a polishing layer.
 15. The method according to claim 10, wherein said movable slurry exhaust mechanism is a rotated baton element and the central axis of said movable slurry exhaust mechanism is parallel to the axis of said head.
 16. The method according to claim 15, wherein said movable slurry exhaust mechanism further comprises a slurry outlet.
 17. The method according to claim 10, wherein said movable chemical solution exhaust mechanism is a movable baton element.
 18. The method according to claim 17, wherein said movable chemical solution exhaust mechanism further comprises a mechanical solution outlet.
 19. The method according to claim 10, wherein said chemical solution further comprises a fluid with small particles.
 20. The method according to claim 10, wherein said chemical solution is unable to cause a bad chemical reaction with wafer surface.
 21. A method for improving polishing surface qualities in chemical mechanical polishing process, said method comprising: laying a polishing pad on a polishing table; using a slurry exhaust system under said polishing table to provide a slurry on said polishing pad, said slurry further comprising a chemical solution which is unable to cause a bad chemical reaction with wafer surface to dilute said slurry; placing a wafer on the polishing pad; and polishing said wafer by using said slurry and said polishing pad.
 22. The method according to claim 21, wherein said polishing table is a table adapted to polishing said wafer.
 23. The method according to claim 22, wherein said polishing table is rotatly movable and is rotated by a revolving spindle which is parallel to the axis of said head.
 24. The method according to claim 21, wherein said wafer further comprises a substrate and a polishing layer.
 25. The method according to claim 21, wherein said slurry further comprises a fluid with small particles. 